Addition polymers derived from norbornene-type monomers exhibit a number of physical and mechanical properties, some of which are highly desirable while others are less desirable or even undesirable. For example, the addition homopolymer of norbornene, i.e., poly(bicyclo[2.2.1]hept-2-ene) exhibits some excellent characteristics such as optical clarity, low moisture absorption, and extremely high thermomechanical resistance having a glass transition temperature of about 380xc2x0 C. On the other hand, this same homopolymer is very brittle requiring improved toughness for many applications. A well known effective method of improving the properties of a polymer is to blend or alloy the polymer with another polymer (or polymers) in order to optimize a given property, e.g., toughness or heat distortion temperature.
A polymer blend is simply a mixture of two or more polymers. The polymer blend, however, can be either immiscible or miscible depending on the value of the free energy of mixing between the polymeric species. For a negative free energy of mixing, the thermodynamics are favorable for a miscible polymer blend; typically a one-phase system results. For a positive free energy of mixing an immiscible polymer blend results giving, typically, a multi-phase system. To change the morphology of a blend, the interfacial properties of the blend must be changed. One method to accomplish this is to add a compatibilizing agent to the blend. According to L. A. Utracki (Polymer Alloys and Blends. Thermodynamics and Rheology. Hanser, Munich, 1989, p. 124) the xe2x80x9cgoal of compatibilization is to obtain a stable and reproducible dispersion which would lead to the desired morphology and properties.xe2x80x9d This can be accomplished in the following ways: 1) add linear, graft, or random copolymers to a polymer blend; 2) coreact in the blend to generate in-situ either copolymer, interacting polymers or interpenetrating networks (by the synthesis of one of the polymers in the presence of the second polymeric constituent); or 3) modify the homopolymers by incorporation of functional groups. In many cases this may result in the formation of a polymer alloy, that is, an immiscible polymer blend having a modified interface or morphology. The morphology of the polymer alloy may be a very fine (sub-micron) dispersion or relatively large depending on the compatibilizer chosen, the amount of compatibilizer added, and the desired properties of the alloy.
Incompatibility is the rule rather than the exception, particularly in the case of hydrocarbon addition polymers derived from norbornene-type monomers (e.g., polynorbornene). Blends of incompatible polymers in most instances form large domains with properties inferior to the constituents, therefore compatibilizer techniques are usually employed to maximize the strengths of the constituents while overcoming their individual deficiencies. Various attempts have been undertaken to prepare polymer compositions that are easily processable and which possess improved physical properties. Compatibilization can provide for specific interactions between polymers. In this regard, methods have focused upon the preparation and use of functionalized polymers having pendant reactive groups which facilitate the grafting of coreactive materials and other polymers to form graft-modified polymers and polymer blends having improved physical properties. Typically a polymer can be functionalized by copolymerizing the monomer with monomer(s) having a functional substituent. However, polyolefins particularly polynorbornene-type addition polymers are generally more difficult to functionalize by copolymerization processes because of the tendency of the polar groups in the monomers to poison the catalyst. To our knowledge no attempts have been made to prepare blends and alloys of polycyclic addition polymers derived from norbornene-type monomers with a variety of other dissimilar polymers.
Accordingly, it would be highly desirable to provide blends and alloys of addition polymerized norbornene-type monomers with other polymer systems.
We have found that it is possible to functionalize polynorbornene-type polymers so as to make them compatible and hence alloyable with a variety of other polymers to generate families of new blends, alloys, and block copolymers with superior balance of properties.
It is a general object of this invention to provide a functionalized polycyclic addition polymer derived from NB-type monomers.
It is another object of this invention to provide polycyclic addition polymers containing a terminal functional group.
It is a further object of this invention to provide polycyclic addition polymers that contains pendant functional groups.
It is still a further object of the invention to provide free radical graft copolymers of polycyclic addition polymers having pendant polyvinylic side blocks and maleic anhydride grafts.
It is another object of this invention to provide in situ polymerization blends of polycyclic addition polymers and reactive and nonreactive elastomeric polymers.
It is still a further object of the invention to provide chlorinated polycyclic addition polymers.
It is another object of the invention to provide miscible blends of polycyclic addition polymers and polystyrene.
In still another object of the invention to provide methods that enable functional end groups and functional pendant groups to be tailored so that desired reactions can be effected.
It is still another object of the invention to prepare olefinic A-B block copolymers with pendant polynorbornene-type side blocks.
It is a further object to react the terminal functional polycyclic addition polymers of this invention with coreactive monofunctional and difunctional polymeric materials to make A-B and A-B-A block copolymers.
We have found that it is possible to functionalize polycyclic addition polymers derived from NB-type monomers to make new materials that can be utilized-as: 1) intermediates for the preparation of other functional containing polymers; 2) segment polymers for the preparation of block copolymers; 3) substrate polymers for the preparation of graft copolymers; 4) as constituent polymers in the preparation of in situ polymer blends; 5) polymers in miscible blends; 6) compatibilizers for polymer blends; and 7) thermosetting systems.
These and other objects of the present invention are accomplished by the following methods and functionalized PNB compositions. As used throughout the specification, the term PNB means polymers represented by structure II below.
The polycyclic addition polymers of this invention are derived from at least one norbornene-type (NB-type) monomer having the following structure: 
wherein R1 to R4 independently represent hydrogen, linear and branched (C1-C20)alkyl; hydrocarbyl substituted and unsubstituted (C5-C12)cycloalkyl; substituted and branched (C5-C12)cycloalkenyl (C6-C24)aryl; (C7-C15)alkyl; linear and branched (C2-C20)alkenyl; (C3-C20)alkynyl; any of R1 and R2 or R3 and R4 can be taken together to form a (C1-C10)alkylidene group; R1 and R4 when taken together with the two ring carbon atoms to which they are attached can represent saturated and unsaturated cyclic groups of 4 to 12 carbon atoms or any aromatic ring of 6 to 17 carbon atoms; and n is 0, 1, 2, 3, or 4. When n is 0 in structures I and II and in all structures in the specification and claims, it will be recognized that a bicyclic structure will be present and that substituents R1 to R4 will be attached to the respective ring carbon atoms in the cicyclic ring. By hydrocarbyl is meant that the substituent is composed solely of carbon and hydrogen atoms. Representative hydrocarbyl substituents include linear and branched (C1-C10)alkyl, and linear and branched (C2-C15)alkenyl.
The term NB-type monomer as used throughout the present specification is meant to include norbornene as well as any higher cyclic derivative thereof so long as the monomer contains at least one norbornene moiety as set forth in the structure above.
Representative monomers of structure I include 2-norbornene, 5-methyl-2-norbornene, 5-hexyl-2-norbornene, 5-decyl-2-norbornene, 5-phenyl-2-norbornene, 5-naphthyl-2-norbornene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 5-hexenyl-2-norbornene dicyclopentadiene, dihydrodicyclopentadiene, tetracyclododecene, methyltetracyclododecene, tetracyclododecadiene, dimethyltetracyclododecene, ethyltetracyclododecene, ethylidenyl tetracyclododecene, phenyltetracyclododecene, trimers of cyclopentadiene (e.g., symmetrical and asymmetrical trimers).
The polycyclic polymers (NB-type polymers or PNB""s) derived from the monomers described under structure I above are represented by the following structure: 
wherein R1 to R4 and n are defined above; and a represents the number of repeating units present in the polymer. This invention contemplates homopolymers and copolymers containing the repeat unit described generally under structure II. The structural repeat units derived from the NB-type monomers of this invention insert into the polymer backbone via linkages derived from the double bond present in the norbornene moiety (i.e., 2,3-enchainment). The repeating units are joined directly to one another without any intermediate linkages between units. The polymer backbone is free of olefinic unsaturation.
In the first embodiment of this invention functionalized PNB""s can be prepared from PNB""s containing terminal olefinic unsaturation. By terminal olefinic is meant that the PNB is terminated with an xcex1-olefin, isobutylene, or diisobutylene as follows: 
wherein R5 is hydrogen or linear or branched (C1-C10)alkyl. Representative R5 substituents include hydrogen, methyl, ethyl, propyl, i-propyl, butyl, t-butyl, and pentyl radicals. Terminal olefinic unsaturation and terminal isobutylene, or diisobutylene polynorbornene-type polymers containing unsaturation can be prepared by the novel chain transfer mechanism of the catalyst system of copending patent application U.S. Ser. No. 08/829,863 filed on Nov. 15, 1994, which is incorporated herein by reference. Terminal unsaturated PNB""s such as vinyl-terminated and isobutylene-terminated PNB, provide an entry point to access a host of functionalized PNB""s specifically at the polymer chain end. These polymer chain end functional PNB""s can be accessed by a variety of stoichiometric as well as catalytic reactions known to those skilled in the art of carbon-carbon double bond chemistry.
PNB""s having terminal olefinic moieties can be functionalized by formation of, but are not limited to, epoxy, monoalcohol, diol, anhydride, aldehyde, carboxylate, dicarboxylate, amide, nitrile, amine, and sulfonate moieties.
Terminal PNB-epoxides can be prepared from the reaction of an xcex1-olefin or isobutylene terminated PNB and m-chloro-perbenzoic acid (MPBA) in an appropriate solvent as follows: 
The terminal PNB-epoxides can also be prepared by reaction with other hydroperoxide or hydroperoxide mixtures such as t-butylperoxide or hydrogen peroxide and acetic acid mixtures as related by J. H. Bradbury and M. C. Seneka Perera in Ind Eng. Chem. Res. 1988, 27, 2196. The PNB-epoxides can also be prepared via catalytic epoxidations using well-known transition metal catalysts as detailed by K. B. Sharpless and T. R. Verhoeven in Aldrichimica Acta 1979, 12, 63.
The terminal PNB-monoalcohol can be prepared from the reaction of vinyl terminated PNB with 9-borobicyclo[3.3.1]nonane (9-BBN) followed by hydrogen peroxide, and NaOH in an appropriate solvent as follows: 
The terminal anhydride-PNB can be prepared by the reaction of isobutylene terminated PNB and maleic anhydride (ene reaction). The reaction is schematically represented as follows: 
The terminal anhydride-PNB can be further reacted under acidic or basic conditions to form a dicarboxylate functional-PNB.
The diol terminated PNB can be prepared by the reaction of an epoxy terminated PNB with HClO4/H2O (perchloric acid). The reaction scheme is set forth below: 
The aldehyde terminated PNB can be prepared from the hydroformylation of an isobutylene terminated PNB as shown below: 
It is also contemplated that the aldehyde end group moiety can be further reacted with hydrogen to form the alcohol-terminated PNB catalytically. This transformation is well-known to those skilled in the art of the xe2x80x9coxoxe2x80x9d process as described in Principles and Applications of Organotransition Metal Chemistry by J. P. Collman, L. S. Hegedus, J. R. Norton, and R. G. Finke, University Science Books, Mill Valley Cailf., 2nd ed., 1987, p. 621 and in Homogeneous Catalysis by G. W. Parshall and S. D. Ittel, John Wiley and Sons, 2nd ed., 1992, p. 106. This transformation is typically carried out using a suitable cobalt or rhodium catalyst such as phosphine-modified dicobalt octacarbonyl and phosphine-modified rhodium complexes.
Further catalytic transformations of the terminal olefinic unsaturated PNB are contemplated such as, but not limited to, azacarbonylation, hydrocarboxylation and hydrocyanation to yield amide-functional, carboxylate or carboxylic acid-functional, and nitrile-functional PNB""s, respectively. Azacarbonylation is typically carried in the presence of mainly nickel and cobalt catalysts and in presence of ammonia, aliphatic amines, or aromatic amines as related by I. Tkatchenko in Comp. Organomet. Chem. G. Wilkinson, F. G. A. Stone, E. W. Abel, eds., Pergamon, 1982, vol. 8, p. 172. Hydrocarboxylation is typically carried out in the presence of a cobalt catalyst such as dicobalt octacarbonyl under CO pressure in either an alcohol (to form the carboxylate) or water (to form the carboxylic acid) cosolvent as related in Homogeneous Catalysis by G. W. Parshall and S. D. Ittel, John Wiley and Sons, 2nd ed., 1992, p. 101. Hydrocyanation is typically carried out in the presence of nickel tetrakis(phosphine) or phosphite complexes and hydrogen cyanide as related in Homogeneous Catalysis by G. W. Parshall and S. D. Ittel, John Wiley and Sons, 2nd ed., 1992, p. 42. It is further contemplated that the nitrile functionality can be hydrogenated to the terminal amine functionality using stoichiometric reagents such as lithium aluminum hydride or catalysts such as RhH(PPri3)3 and H2 or Raney nickel and sodium borohydride in alcohols.
A further embodiment of this invention includes the sulfonation of the terminal olefinic unsaturated PNB using sulfonation reagents such as acetyl sulfate (a mixture of sulfuric acid and acetic anhydride). This transforms the terminal olefinic unsaturated PNB into a sulfonic acid that may be neutralized using bases such as lithium hydroxide or magnesium hydroxide to form ionomeric species.
The acrylate terminated PNB can be prepared by the reaction of a hydroxy-terminated PNB and acryloyl chloride as shown by the following reaction scheme: 
The terminal olefinic, isobutyl, and diisobutyl PNB polymers used in the preparation of terminal functional PNB""s of this invention can be prepared from a reaction mixture comprising one or more norbornene-type monomer(s), a [(crotyl) Ni(COD)][LPF6] catalyst in the presence of a chain transfer agent (CTA) all in an appropriate solvent. The CTA is selected from a compound having a terminal olefinic double bond between adjacent carbon atoms, wherein at least one of the adjacent carbon atoms has two hydrogen atoms attached thereto. The CTA is represented by the formulae: 
wherein R5 is as defined above. Preferred CTA""s include ethylene, propylene, isobutylene, 4-methyl-1-pentene, 1-hexene, 1-decene, and 1-dodecene.
The CTA""s incorporate exclusively as terminal end-groups on each PNB chain. The CTA""s do not copolymerize into the PNB backbone. A representative structure is shown below: 
wherein Q is derived from the CTA defined above.
The terminal functional PNB polymers of this invention can be reacted with any coreactive moiety containing a functional group that is reactive with the terminal functional group on the PNB polymer. The coreactive moiety can be monomeric, oligomeric, or polymeric and the term as used herein refers to coreactive plasticizers, lubricants, impact modifiers, heat distortion modifiers, processing aids, compatibilizers, and polymers.
The terminal functional PNB""s of this invention can be utilized to prepare A-B and A-B-A block copolymers of PNB with coreactive polymer oligomers or macromonomer having a functional group (preferably terminal functional) that is reactive with the terminal functional group on the PNB.
Exemplary of the block copolymers that can be prepared in accordance with this invention is the reaction of a monohydroxy terminated PNB with a monofunctional moiety (e.g., acid chloride) to give an A-B block copolymer as follows: 
wherein R6 polybutadiene, polyisoprene, polystyrene poly(xcex1-methylstyrene), polymethylmethacrylate, polyalkylacrylates such as polybutylacrylate, or other anionically polymerized polymers that can be functionalized to an acid.
If a difunctional acid chloride is employed, an A-B-A block copolymer can be obtained as follows: 
wherein R7 represents polybutadiene, polyisoprene, polystyrene, poly(xcex1-mmethylstyrene), polybutylacrylate, polyester, polyamide, polyamic ester, polyether.
If a monofunctional isocyanate is employed, the PNB will be end-capped with an urethane group as follows: 
wherein R8 is hydrocarbyl and silyl such as (trialkoxy)silyl isocyanate. By hydrocarbyl is meant linear and branched (C1-C15)alkyl, linear and branched (C1-C2)alkenyl, (C6-C20)aryl, and araalkyl (C6-C15).
The case of a diisocyanate the following A-B-A block copolymer is formed: 
wherein R9 represents a polyurethanes, polyureas, and polythioureas.
Vinyl terminated PNB can be subjected to a hydrosilation reaction in the presence of a platinum catalyst as related by J. L. Speier in Advances in Organometallic Chemistry 1979, Vol. 17, p. 407, to give A-B-A block copolymers wherein the PNB comprises the A blocks with a polysiloxane B block as follows: 
wherein R10 independently represents (C1-C15)alkyl, (C6-C20)alkyl, or (C6-C24)aralkyl, m is 2 to 10, a represents the number of repeating units of the siloxane unit.
In this same manner epoxy terminated PNB can be reacted with a difunctional acid terminated polybutadiene (HOOC-polybutadiene-COOH) or an aliphatic diacid (HOOCxe2x80x94Rxe2x80x94COOH) to give A-B-A block copolymer products.
In addition, polymers with terminal-olefin unsaturation such as, for example, allyl terminated polyisobutylene can be directly appended to the terminal end of a PNB via the chain transfer mechanism utilized to prepare the olefin terminated PNB starting materials of this embodiment. In this manner a variety of PNB A-B block copolymers can be synthesized. Other polymers that can function as polymeric chain transfer agents are olefinic terminated polyolefins such as polyethylene, polypropylene, and ethylene/propylene (diene) rubber.
In another embodiment of this invention functionalized PNB""s can be prepared from PNB starting materials that contain olefinic unsaturation that is pendant from the polycyclic structural repeat unit (i.e., pendant olefinic PNB). Groups that provide pendant olefinic unsaturation are (C1-C10)alkylidene (C2-C10)alkenyl wherein the unsaturated double bond is at the terminal end of the substituent (C5-C8)cycloalkenyl, and a (C5-C8) fused ring cycloalkenyl ring structure. Preferred substituents include ethylidene, vinyl, cyclohexenyl, and a cyclopentene ring taken together with two adjacent carbon atoms on the polycyclic repeating unit (i.e., dicyclopentadiene). Representative PNB""s with pendant unsaturation are set forth as follows: 
where a represents the number of repeating units in the polymer. It should be understood that the PNB""s so functionalized can include repeat units set forth under formula I.
The foregoing polymers are polymerized from one or more of monomers selected from formula I. Homopolymers and copolymers are contemplated within the scope of this embodiment.
The PNB""s with pendant unsaturation are made by copolymerization of the respective comonomer constituents using nickel-based catalysts. The nickel-based catalyst system may include the addition of nickel-(II) ethylhexanoate to a dichloroethane solution of the comonomers and a suitable chain-transfer agent (an alpha-olefin such as 1-decene) if desired to control molecular weight, followed by the addition of a trialkyl aluminum (e.g., triethylaluminum, tri-iso butylaluminum, etc.), followed by a chlorinated activator (e.g., hexachloroacetone, chloranil, etc.). Additionally the nickel-based catalyst system may include the addition of a Brxc3x8nsted acid such as HSbF6 to nickel (II) ethylhexanoate, followed by addition of this mixture to a dichloroethane solution of the comonomers (optionally including a chain-transfer agent), followed by addition of BF3xc2x7Et2O and a trialkylaluminum such as triethylaluminum.
As with the PNB""s containing terminal olefinic unsaturation, the PNB""s containing pendant unsaturation can be functionalized to form epoxy, monoalcohol, diol, carboxylate, anhydride, sulfonate, amide, nitrile, and amine. The PNB""s containing pendant olefinic groups can be prepared in the same manner as described above for the PNB""s containing terminal olefinic groups. The following reaction scheme is illustrative of pendant olefinic PNB functionalization via epoxidation. 
The pendant epoxide functionality can be converted to the diol as described above in the terminal functional epoxide embodiment. As with the terminal functional epoxy PNB""s, the PNB""s with pendant epoxide functionality can be coreacted with acid and diacid chlorides set forth above to give A-B and A-B-A block copolymers. In general the epoxide pendant functionality undergoes any reaction that the monoepoxides discussed above can undergo.
Polynorbornene copolymers such as PNB/ENB, PNB/vinyl norbornene, PNB/cyclohexyl norbornene and PNB/DCPD, most preferably PNB/DCPD copolymer containing reactive unsaturated groups and whose molecular weight (Mn) ranges from 225 to 15,000 g/mole, preferably range being from 1,000 to 5,000 g/mole, can be epoxidized using peracids such as peracetic acid, perbenzoic acid, m-chloro perbenzoic acid, most preferably m-chloro perbenzoic acid. Such epoxidized PNB copolymers can be used as multifunctional epoxy material in standard epoxy formulations to obtain a three dimensional insoluble and infusible network. Thus epoxidized PNB copolymers can be dissolved in both aromatic and aliphatic di and multifunctional epoxy resins such as Epon 828, epoxy phenolic novolac resins, epoxy cresol novolac resins, 3xe2x80x2,4xe2x80x2,epoxycyclohexylmethyl 3,4-epoxy cyclohexanecarbonate, 3,4-epoxy cyclohexyloxirane, 2-(3xe2x80x2,4xe2x80x2-epoxycyclohexyl)-5,1xe2x80x2-spiro-3xe2x80x2,4xe2x80x2-epoxy cyclohexane-1,3-dioxane, the most preferred being the 3,4-epoxy cyclohexyloxirane, and treated with a hardener or curing agent; its choice depending on the processing method, curing condition and the properties desired. The hardener can be either catalytic or coreactive in nature. Catalytic curing agent could be trialkyl amines, boron trifluoride amine complexes and photoinitiated cationic curing agents such as aryldiazonium salts, diaryliodonium salts and onium salts of group VI a elements, especially salts of positively charged sulfur compounds. The most preferred catalytic hardener is the boron trifluoride amine complexes. Coreactive hardeners can be selected from primary and secondary aliphatic and aromatic amines, such as methylene diamine, diaminodiphenyl sulfone, dicynadiamide, diethylenetriamine, triethylenetetramine, preferably diaminodiphenyl sulfone, aliphatic and aromatic mercaptans, di and multifunctional isocyanate, di and multifunctional polyester and polyether carboxylic acids and acid anhydrides. Selected acid anhydrides are phthalic anhydride, tetrahydrophthalic anhydride, methyl tetrahydrophthalic anhydride, hexahydrophthalic anhydride, nadic methyl anhydride and chlorendic anhydride. Thus the epoxy resin containing 10 to 50 weight percent of epoxidized PNB copolymer, the most preferable amount being from 5 to 25 wt. %, can be treated with the hardener at temperatures ranging from about 80xc2x0 C. to about 200xc2x0 C. depending on the hardener of choice and the properties of the network desired. The most preferred temperature being 150xc2x0 C. These PNB copolymer containing materials are phase separated in nature with the domain size of the PNB phase depending on the molecular weight and the functionality of the epoxidized PNB copolymer used. The multifunctional epoxy materials of this invention provide crosslinked materials with high glass transition temperature, low moisture uptake, good electrical properties, good corrosion/solvent resistance and low shrinkage on cure.
Thermosets can also be prepared from the PNB""s having pendant unsaturation by heating the homopolymers or copolymers containing pendant vinyl, alkylidene such as ethylidene, fused ring cyclopentenyl, cyclopentenyl and cyclohexeneyl in the presence of a free radical polymerization initiator such as azobisisobutyonitrile, benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, t-butylperoxyacetoate, and xcex1-cumyl peroxyneodecaneoate in an approate solvent. Suitable solvents include hydrocarbons, halohydrocarbons, aromatics and haloaromatics. The amount of peroxide initiator ranges from about 0.1 to 5.8% by weight after polymer.
Because of the exceptionally high temperature properties of polycyclic addition polymers, it would be useful to blend them with polymer systems of lesser high temperature properties (e.g., heat distortion) in order to raise the heat distortion properties of the target system. However, in order to make an effective blend it is necessary that the polymer components exhibit at least partial miscibility and that some degree of domain size control be achievable. For example, it would be highly desirable to improve the heat distortion temperature of CPVC in order to increase its commercial applicability in high temperature applications, e.g., high temperature pipe, etc. However, CPVC and polynorbornene (non-functionalized) are completely immiscible and the resulting blend exhibits no useful improvement in properties. We have discovered that by introducing epoxy functionality into the PNB (e.g., terminal and/or pendant functional) yields optically clear blends with CPVC which is particularly attractive due to the stabilizing effects of the epoxide moiety agianst dehydrohalogenation.
The CPVC polymers suitable for use in the blends of this invention are readily commercially available. The chlorine content typically ranges from about 61 to about 72 weight percent, preferably from about 63 to about 68 weight percent. The inherent viscosity of the CPVC ranges from about 0.46 to about 1.2, preferably from about 0.68 to about 0.92. The inherent viscosity (I.V.) is a representative measure of the molecular weight of a polymer and is obtained in accordance with ASTM D-1243-66.
In another embodiment of the invention polycyclic polymers derived from NB-type monomers can be modified by grafting free radical polymerizable monomers forming grafted side chains to or from the polycyclic backbone of the PNB. In this embodiment free radically polymerizable monomers containing vinyl unsaturation, i.e., a H2Cxe2x95x90C less than  moiety can be polymerized in the presence of the PNB. The PNB is dissolved in a common solvent for the PNB and vinyl-type monomer. A free radical catalyst initiator is added to the medium and the medium is then heated at elevated temperature to conduct the grafting reaction.
Suitable solvents include hydrocarbons, halohydrocarbons, aromatics, and haloaromatics. Preferred solvents are the aromatics and haloaromatics such as toluene, xylene, benzene, and chlorobenzene. It should be noted that the vinyl-type monomer can function as the solvent so long as it can dissolve the PNB. For example, PNB was observed to be soluble in styrene. In this case an additional solvent is not necessary.
The temperature range of the reaction is from about 80xc2x0 C. to about 150xc2x0 C., preferably about 120xc2x0 C.
Suitable catalytic initiators include organic peroxides such as lauroyl peroxide, benzoyl peroxide, diacetyl peroxide, 5-butyl-peroxyneodeconate, t-butylcumyl peroxyneodecanoate, di-n-propyl peroxydicarbonate, di-t-butyl peroxide, and di-sec-butyl-peroxydicarbonate. The preferred peroxide is di-t-butyl peroxide.
Exemplary of the vinyl-type monomers are styrenes, acrylates, methacrylates, acrylamides, acrylonitriles, and vinyl monomers.
The styrenes are selected from compounds of the formula: 
wherein n is independently 0, 1, 2, 3, 4, or 5, R10 is hydrogen or methyl, and R11 independently represents, hydrogen, halogen, linear and branched (C1-C6)alkyl, C6-C12)alkoxy, (C6-C20)aryl, (C6-C20)aryloxy, xe2x80x94N(R12)2, xe2x80x94SO2R12, where independently represents hydrogen, linear, and branched (C1-C10)alkyl, and (C6-C12)aryl and trifluoromethyl. Preferred compounds of the above formula includes styrene and xcex1-methyl styrene.
The acrylates and methacrylates are selected from compounds of the formula: 
wherein R12 is hydrogen, linear, or branched (C1-C5)alkyl, (C6-C12)alkyl, nitrile, and halogen; R13 is hydrogen, linear, or branched (C1-C20)alkyl, (C1-C10)hydroxy substituted alkenyl.
The acrylamides are selected from compounds of the formula: 
wherein R15 is hydrogen, linear, or branched (C1-C5)alkyl, (C6-C12)aryl, and halo; R16 independently represents hydrogen, linear, or branched (C1-C5)alkyl, and (C6-C12)aryl.
The acrylonitriles are selected from compounds of the formula: 
wherein R17 is hydrogen, linear, or branched (C1-C5)alkyl, (C6-C12)aryl, halo, and nitrile.
The vinyl monomers are selected from compounds of the formula: 
wherein R18 is hydrogen, Cl, Br, and F, linear or branched (C1-C5)alkyl, (C6-C12)aryl; and X is Cl, Br, F, linear or branched (C1-C5)alkyl, (C2-C20)alkenyl, (C6-C12)aryl, (C6-C18 aryl ethers, xe2x80x94OAc, aryl ethers, tri (C1-C10)alkoxysilanes, and allyl (C1-C10)trialkoxysilanes.
In a preferred embodiment, is has been discovered that the PNB""s containing pendant unsaturation on the PNB backbone enhance the grafting of the free radically polymerized side chains on to the PNB backbone. It is thought that the allylic hydrogen atoms (exclusive of the bridgehead hydrogens) provides an active site for more efficient grafting of the free radically polymerized vinyl-type monomer.
Another embodiment of this invention concerns a process and polymer composition in which an elastomer is solution blended with norbornene-type monomer(s) in a suitable solvent (i.e., a solvent that dissolves the norbornene-type monomer, the resulting norbornene-type polymer, and the elastomer but does not interfere with the polymerization). The norbornene-type monomer is then polymerized by addition of a multicomponent catalyst system comprising a Group VIII transition metal compound in combination with an organoaluminum compound and an optional third component selected from Lewis acids, Brxc3x8nsted acids, and halogenated compounds. Such catalysts are described in copending patent application U.S. Ser. No. 08/829,863 filed on Nov. 15, 1994 which is herein incorporated by reference. In this one-step process, a more intimate mixture or blend of the elastomer and the resulting polynorbornene is formed than can be obtained by melt blending. This process referred to herein as nonreactive in situ blending because no covalent bonding occurs between the subsequently formed PNB and elastomer. The same morphology is obtained by solution blending a completely polymerized PNB and mixing with an elastomer. Likewise, unreacted blends with suitable plasticizers have been found to be a miscible with NB-type polymers exhibiting a reduced glass transition for the blend. Suitable plasticizers include hydrogenated cyclopentadiene oligomers (sold under the trademark Escorez(copyright) by Exxon Chemicals) and at linear and branched alkane ranging from C14-C34, most preferably C24-C30.
In this case an elastomer is defined as any polymeric material which has a low glass transition temperature (Tg). Low glass transition temperature is defined as Tg""s below room temperature. Examples of elastomers include butyl rubber, polyisobutylene, and ethylene/propylene (diene) rubber. Other suitable elastomers include polysiloxanes (e.g., polydimethylsiloxane, etc.) and poly(meth)acrylates (e.g., polybutylacrylate, polybutylmethacrylate, etc.).
Another class of polymers having elastomeric properties which are suitable for forming unreactive in situ blends with norbornene-type polymers are the hydrogenated A-B-A block copolymers of styrene-butadiene-styrene available under the KRATON(copyright) G trademark. These thermoplastic elastomers are especially attractive since they form blends with the norbornene-type polymers of this invention and are transparent due to a very small (i.e., less than the wavelength of visible light) particle size morphology.
A further embodiment of this invention is a process and composition in which an elastomer containing either pendant unsaturation or end group unsaturation is solution blended with norbornene-type monomer(s) in a suitable solvent (i.e., a solvent that dissolves the monomer and the elastomer but does not interfere with the subsequent polymerization). The norbornene-type monomer is then polymerized by addition of the above-referenced catalyst systems. In this manner a chemical bond is formed between the growing norbornene polymer and the elastomer since the above described catalysts undergo a unique chain transfer reaction forming an A-B comb or di-block copolymer. This process is referred to herein as reactive in situ blending.
Examples of suitable elastomers include butadiene and isoprene rubber, allyl-terminated polyisobutylene, or ethylene/propylene (diene) rubber, siloxanes all of which can contain either pendant or end group unsaturation. Another class of polymers having elastomeric properties which are suitable for forming reactive in-situ blends with the PNB""s of this invention are the A-B-A block copolymers of styrene-butadiene-styrene available under the KRATON(copyright) D trademark.
Suitable unsaturation is defined by those carbon-carbon double bonds which will undergo chain-transfer using the catalysts above described. The double bonds include vinyl groups and vinylidene groups.
A further embodiment of this invention is a process in which a terminal functional PNB macromonomer is copolymerized with an olefin using a suitable Ziegler-Natta catalyst systems to make an A-B comb block copolymer with pendant polynorbornene side blocks. A suitable terminal functional PNB includes vinyl-terminated PNB. In this case suitable olefin monomers include ethylene, propylene, butene, and longer chain alpha-olefins and mixtures thereof Suitable Ziegler-Natta catalyst systems include titanium-based catalysts such as TiCl3 in combination with diethylaluminum chloride, supported titanium catalysts such as TiCl4 on MgCl2 in combination with AlEt3, vanadium catalysts such as VOCl3xe2x88x92x(OR)x (where x=0-3 and R is a hydrocarbyl substituent such as methyl, ethyl, propyl, butyl, aryl, alkenyl, or alkaryl) in combination with AlR3xe2x88x92xClx (where x=0-2 and R is a hydrocarbyl substituent such as methyl, ethyl, propyl, butyl, aryl, alkenyl, or alkaryl), or a metallocene-type catalyst in combination with a methaluminoxane cocatalyst or in combination with a trialkylaluminum and an activator. Suitable metallocene catalysts include those catalysts based on Group IV metals (titanium, zirconium, and hafnium) containing one or two cyclopentadienyl ligands that can be unsubstituted, substituted, bridged or unbridged. Typical examples include but are not limited to bis(cyclopentadienyl) zirconium dichloride, ethylene-bridged bis(indenyl)zirconium dichloride, dimethylsilyl-bridged bis(cyclopentadienyl) zirconium dichloride, and dimethylsilyl-bridged bis(indenyl)zirconium dichloride. Suitable activators include strong neutral Lewis acids and ionic Brxc3x8nsted acids. Examples of the former activators include, but are not limited to, tris(perfluorophenyl)boron, etc. Examples of the latter class of activators include, but are not limited to N,N-dimethyl anilinium tetrakis(perfluorophenyl)borate and trityl tetrakis(perfluorophenyl)borate, etc. The metallocene catalysts may be used as unsupported or supported catalysts. Typical supports include silica or alumina.
It is further contemplated within the scope of this invention that polynorbornenes containing isobutylene-terminal functionality react with isobutylene in the presence of a suitable cationic initiator to form a comb-type A-B block copolymer with polynorbornene pendant side blocks. Suitable cationic initiators include, but are not limited to, Lewis acids such as ethylaluminum dichloride, aluminum trichloride, boron trichloride, titanium tetrachloride, etc.
It is well known that polymers can be chlorinated. Examples of commercial chlorinated polymers include chlorinated polyethylene and chlorinated polyvinylchloride. Typically, these polymers are chlorinated by addition of chlorine to the polymer in the presence of UV light or heat in solution, suspension, or in the solid state. Chlorination imparts some desirable properties to the polymers. For example, in the case of polyethylene, chlorination reduces the flammability of the material. In the case of polyvinylchloride, chlorination increases the glass transition temperature of the polymer as well as the commercially important heat distortion temperature. In addition to these properties, chlorination of the polymer changes its solubility characteristics and its compatibility with other polymers. Heretofore it has not been demonstrated that PNB can be chlorinated. In this invention we have shown that it is possible to chlorinate the polycyclic addition polymers of this invention and this is to be considered yet another embodiment of this invention. Chlorosulfonation of the polycyclic addition polymers is also contemplated in this invention. Typically this is done by addition of chlorine and sulfur dioxide or addition of sulfuryl chloride to the PNB polymer in the presence of UV light or heat.
As outlined previously, one method of compatibilizing two polymers is to add a random copolymer containing comonomer constituents that can form specific interactions with the two or more polymers to be blended. This type of strategy can be followed for the polynorbornenes of the present invention. Thus, it is a further embodiment of this invention to randomly copolymerize norbornene with selected comonomers that will allow specific interactions with two or more selected polymers to form blends and/or alloys between the two or more selected polymers. An example of this type of strategy is exemplified by the copolymerization of norbornene with 5-phenylnorbornene to form a random copolymer which in turn can be mixed with any aryl-containing (co)polymer such as polystyrene or polyxcex1-methylstyrene. In this case the specific interactions between polystyrene and the norbornene/5-phenylnorbornene copolymer are characterized by xcfx80xe2x80x94xcfx80 interactions between the phenyl group of the aryl-containing polymer and the phenyl group of the 5-phenylnorbornene of the norbornene copolymer. Another example may include, but is not limited to, copolymerization of norbornene with acrylate-functional norbornenes to form blends with chlorinated polymers such as polyvinylchloride. In this case, the specific interactions between the chlorinated polymers and the acrylate-functional polynorbornene is characterized as dipole-dipole. A further example may include, but is not limited to, copolymerization of acid-functional norbornenes with norbornene followed by neutralization with a base such as lithium or magnesium hydroxide to form blends with polyalkylene oxides such as polyethylene oxide or polypropylene oxide. In this case, the specific interactions between the polyalkylene oxide and the neutralized acid-functional norbornene copolymer is characterized as ion-dipole.
It is well known to those skilled in the art that maleic anhydride grafting onto polyolefins, such as polyethylene and propylene, is often performed to improve physicochemical properties of typically hydrophobic polymers to promote adhesion, dyability, and to provide functionality for other chemical modifications (see B. C. Triveldi and B. M. Culbertson, Maleic Anhydride, Plenum Press, New York, 1982). The grafting is typically accomplished using mechanochemical (such as extrusion), mechanochemical with free-radical initiators, free radical, ionic, and radiation-initiation techniques. Depending on the chemical nature of the polymer to be grafted a free radical, xe2x80x9cenexe2x80x9d (indirect substituting addition), or Diels Alder reaction route may be employed. Grafting of maleic anhydride onto polyethylene and polypropylene using solution free radical methods typically use xylene as a solvent and benzoyl peroxide as an initiator and take place between 90 and 130xc2x0 C., or use refluxing chlorobenzene (or dichlorobenzene) with benzoyl peroxide, t-butyl peroxybenzoate, or di-t-butyl peroxide. Literature also shows the subsequent reaction with amines produced detergent additives for lubricants (Shell International, Netherland Patent No. 2,969 (1965)). Typically the grafted maleic anhydride content is between 0.1 and 5 wt. %. Extrusion grafting typically occurs at typical melt extrusion temperatures for polyethylene and polypropylene (T greater than 200xc2x0 C.) and may also occur in the presence of a free radical initiator. It has been observed that maleic anhydride grafted polypropylene has shown an increased dispersability with Nylon 6 (F. Ide and A. Hasegawa, J Appl. Polym. Sci., 18(4), 963 (1974)) through reaction of the maleic anhydride moiety on the polypropylene with the nylon amino residues. Grafting has been shown to occur for a variety of polymers including polyethylene, polypropylene, ethylene propylene copolymers, polystyrene, polyvinylchloride, polyisobutylene, polyvinylacetals, polyisoprene, polybutadiene, polytetrafluoroethylene, polyacrylates, other poly-alpha-olefins and polymers containing furfuryl residues.
To our knowledge norbornene-type addition polymers have heretofore never been synthesized. We have found that the homo- and copolymeric PNBs of this invention can be reacted (through a free radical mechanism) with maleic anhydride to form grafts of succinic anhydride. The PNB/succinic anhydride graft copolymers thus prepared can be further reacted with a variety of moieties that contain coreactive functionalities with succinic anhydride.
The polycyclic polymers may be grafted with an unsaturated carboxylic acid or a derivative thereof. Examples of the unsaturated carboxylic acid used herein include acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid and nadic acid (endocisbicyclo[2,2,1 ]hept-5-ene-2,3-dicarboxylic acid). The derivatives of the above-mentioned unsaturated carboxylic acids are unsaturated carboxylic acid anhydrides, unsaturated carboxylic acid halides, unsaturated carboxylic acid amides, unsaturated carboxylic acid imides and ester compounds of unsaturated carboxylic acids. Concrete examples of these derivatives include maleyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate and glycidyl maleate.
These graft monomers exemplified above may be used either singly or in combination.
Of the above-exemplified graft monomers, preferred are unsaturated dicarboxylic acids or derivaties thereof, and particularly preferred are maleic acid and nadic acid or acid anhydrides thereof.
The PNB/succinic anhydride graft copolymers of this invention can be prepared by dissolving the PNB and maleic anhydride in an appropriate solvent. Suitable solvents such as hydrocarbons, halohydrocarbons, aromatics and haloaromatics, preferred solvents are the aromatics and haloaromatics such as toluene, xylene, benzene, chlorobenzene, and o-dichlorobenzene. The reaction solution is then a sufficient amount of a suitable peroxide initiator. Suitable initiators include organic peroxides such as lauroyl peroxide, benzoyl peroxide, diacetyl peroxide, 5-butyl-peroxyneodeconate, t-butylcumyl peroxyneodecanoate, di-n-propyl peroxydicarbonate, and di-sec-butyl-peroxydicarbonate. The maleic anhydride is employed in an amount of up to about 10 percent by weight of the PNB polymer. Preferably maleic anhydride is utilized in the range of from about 0.1 to 5 percent by weight of the PNB polymer. The grafting reaction is conducted in a temperature range from about 120xc2x0 C. to 220xc2x0 C., preferably from 140xc2x0 C. to 200xc2x0 C., and most preferable from 160xc2x0 C. to 180xc2x0 C.
The PNB/succinic anhydride graft copolymers can be further reacted with polyamides, particularly, amine terminated polyamides, such as, for example, Nylon 66, Nylon 12, and Nylon 6. The PNB/MA-polyamide graft copolymer can be formed from solution or reactive extrusion.
In the solution process the PNB/MA graft copolymer and the polyamide (nylon) are dissolved in an appropriate solvent or mixture of solvents. The reaction medium is heated at a temperature range from about 20xc2x0 C. to about 200xc2x0 C., preferably about 130xc2x0 C.
In the melt process the maleic anhydride, PNB polymer, and polyamide components can be reactive processed on an extruder, mill or any of the well known thermal mechanical mixing devices commonly used in the plastic compounding industry. The components react in the melt to give a PNB/succinic anhydride/polyamide graft copolymer. The temperature employed should be above the Tg of the PNB, but of course should be below the degradation temperature of the PNB. It will be understood that different homo- and copolymers of PNB will have differing Tg""s and degradation temperatures. Typically, the temperature range employed can be from about 150xc2x0 C. to about 350xc2x0 C.
Other polymer resins such as amine terminated silicones, amine terminated polypropylene oxides, and amine terminated polybutadienes can be coreacted with the PNB/succinic anhydride graft copolymers of this invention, in a similar manner as discussed hereinabove.
As discussed above any functionality that is reactive with the PNB/succinic anhydride functionality can be coreacted therewith to prepare novel PNB graft copolymers. Exemplary of the coreactive functional groups that can be reacted on the PNB backbone are as follows: